Most cats quickly learn how to use the litter box. Kittens who watch their mothers may pick up on the habit. If your kitten does not use the litter box, train them. Cats may have accidents if their litter box is dirty, or if they are under stress. Common causes of cat stress are moving to a new home, new visitors, too many cats in the household, you leaving for a long period of time or new furniture. Properly training a cat to use the litter box may not prevent stress related accidents from happening.
Place the litter box in a quiet area away from traffic. Cats may be too nervous to venture into the litter box if people are in the area. Placing the box in an area away from traffic and loud noises is ideal. Cats also do not like their litter box to be near their food and water.
Clean the litter box often. If you use scoop-able cat litter, scoop the box out daily. Other litter can be thrown out and replaced. Cats often have accidents in other areas of the home due to dirty litter boxes.
Show your cat where the litter box is. Put her inside of it. Let her sniff around and scratch. If she doesn't act interested, try scratching the litter with your finger so she hears the sound. You might also move her paw around for her. If she still isn't interested, repeat this process every hour until she finally uses the litter box.
Purchase multiple litter boxes if you have multiple cats. If your cat shares the box with other cats and one of them is not using the litter box, consider having a special litter box only to be used by the cat having problems. Some cats may not want to share their litter box with others.
Clean accidents up immediately. Use a solution of half vinegar and half water to eliminate the odor. If the odor is gone, it may prevent the cat from returning to that spot. Sometimes moving feces from outside the litter box to inside the box teaches the cat where the feces should go.